Atrial fibrillation is increasingly common with advancing age. During atrial fibrillation, the heart's two upper chambers (the atria) beat chaotically and irregularly out of coordination with the two lower chambers (the ventricles) of the heart. The result is an irregular and often rapid heart rate that causes poor blood flow to the body and symptoms of heart palpitations, shortness of breath and weakness. It generates tiny blood clots which are sent around the body and can trigger a stroke. It accounts for a quarter of strokes in the elderly.
Atrial fibrillation is a major cause of hospitalisation and mortality and affects about 2.5 million people in the United States, as well as 4.5 million people in the European Union and is emerging as a growing public health concern because of the aging of the population
Follow up analysis of a previous study presented at the Heart Rhythm Society Congress in San Francisco showed earlier hopes on the new drug were well-founded indeed.
Doctors claim it is the first advance in 20 years in tackling atrial fibrillation and atrial flutter.
Many need drug treatment to stabilise a fast and erratic heartbeat that can be deadly or cause serious complications such as angina and heart failure.
Some patients go on long-term drug therapy including digoxin which slows the heart but does not restore its regularity and has been linked to higher death rates.
ATHENA trials of the new Sanofi drug had yielded positive results. It was the largest double blind randomised study in patients with atrial fibrillation and was conducted in more than 550 sites in 37 countries and enrolled a total of 4,628 patients.
(ATHENA is so called because it was A
placebo-controlled, double-blind, parallel arm T
rial to assess the efficacy of dronedarone 400 mg bid for the prevention of cardiovascular H
ospitalization or death from any cause in patiEN
ts with A
trial fibrillation/atrial flutter).
After treatment lasting at least a year, the researchers found a 30 per cent cut in risk of death from cardiovascular causes among those taking the new drug.
They also had a 25 per cent cut in risk of being hospitalised for the first time with any kind of heart problem and a 24 per cent lower risk of being taken into hospital or dying from any cause during the study period.
Lead researcher Dr Stefan Hohnloser at J.W. Goethe University in Frankfurt, Germany, said 'ATHENA is the first large trial of an antiarrhythmic agent that measures if an antiarrhythmic drug can reduce the composite outcome of the time to first cardiovascular hospitalisation or death from any cause in an atrial fibrillation population.
'The positive effects of dronedarone are significant and extremely important to the field of cardiology.'
The most frequently reported adverse events of dronedarone vs placebo induced gastro-intestinal effect (26% vs 22%), skin disorder (10% vs 8%, mainly rash) and increased blood creatinine (4.7% vs 1%). The mechanism of blood creatinine increase (inhibition of creatinine secretion at the renal tubular level) is well defined. Compared to placebo, dronedarone showed low risk of pro-arrhythmia and no excess of hospitalisations for congestive heart failure. There was a similar rate of study drug discontinuation between the two study groups.
"ATHENA is truly a landmark trial, that marks a paradigm change for the management of atrial fibrillation," said Dr Christopher Cannon, a Senior Investigator in the TIMI Study Group at Brigham and Women's Hospital, who was not involved in the study. "Atrial fibrillation is a very common disease, and our prior treatment options have been focused only on symptom relief and a hope to not do harm, which has been the problem with prior antiarrhythmic drugs. Now, with a highly significant reduction in death or hospitalisation, as well as a 45% reduction in arrhythmic death or 30% cardiovascular death, dronedarone may become a first line treatment of atrial fibrillation".
British experts said the trial findings were significant and could change the way patients are treated.
Dr Edward Rowland, consultant cardiologist at The Heart Hospital, London, who is president of HRUK (Heart Rhythm UK), said 'Atrial Fibrillation is an enormous health problem. The impact on patients and the cost to the NHS is vast. Medications are the mainstay of treatment but those currently available have limited effectiveness.
'Hundreds of thousands of people suffer with AF so a 25 per cent reduction in deaths from any cause, whichever way you look at it, could end up with thousands of lives saved.'
Dr Jonathan Sahu, Lead Cardiologist and Consultant Electrophysiologist, Sheffield Teaching Hospital, said 'This is the first time we have seen a drug that is highly effective in this patient population without causing serious adverse events or death."
Trudie Lobban, chief executive office of the Atrial Fibrillation Association, said 'This result is really exciting news for patients and their carers.
'Atrial fibrillation has such a significant impact on all those affected, as well as a huge economic cost for the healthcare system. The future availability of a drug such as dronedarone will be welcome news.'